Has this been successfull using an external CD/DVD-ROM? I'm having a similar situation trying to install Solaris 9 on a SunFire V210 with no OS pre-installed. Trying to find out how to prepare a pc...
Have you checked that you don't have any error messages logged (boot permitting of course)? I just read over at another site of a similar case, where the user went through his /var/adm/messages...